1. Field of the Invention
The present invention relates to a printer apparatus.
2. Discussion of the Background
The printer apparatus (inkjet printer) is structured so that, while a carriage on which printer heads are mounted is relatively moved, for example, in a lateral direction with respect to a printing medium reciprocatedly, ink is ejected from an ejection nozzle formed on an under face of the printer head to perform predetermined printing on a surface of the printing medium. Respective printer heads for respective colors, for example, of magenta (M), yellow (Y), cyan (C) and black (K) (hereinafter, these four colors are referred to as “basic color”) are mounted on the carriage, inks ejected from these printer heads are adhered to the surface of the printing medium with predetermined densities to express various colors. Further, in the above-mentioned printer apparatus, a mechanism referred to as a maintenance device is commonly provided in which ink within the ejection nozzle is sucked in a state that an under face of the printer head is covered to recover to a state that ink is capable of being ejected normally.
Recently, there has been a demand that printing with further fine colors is performed and, in order to attain this demand, a printer apparatus has been proposed in which, for example, in addition to the basic colors, printer heads for orange, blue and the like (hereinafter, referred to as “special color” to the basic colors) are mounted on the carriage. For example, in FIG. 2 of Japanese Patent Laid-Open No. H09-11508, a printer apparatus is disclosed in which inkjet heads 9C, 9M, 9BK, 9OR and 9BL corresponding to the basic colors, orange and blue are mounted on a carriage 9 which is movably supported.
An example of a conventional printer apparatus is shown in FIG. 12 in which special colors are mounted in addition to the basic colors as described above. FIG. 12 is a perspective view showing a vicinity of a printing device 600 of a printer apparatus 500. The printing device 600 is structured so that printer heads 620M, 620Y, 620C, 620K, 620OR and 620BL corresponding to the basic colors, orange and blue which are arranged side by side in the lateral direction are mounted on a carriage 610 which is attached so as to be movable in the lateral direction with respect to guide rails 510 on an upper side of a flat plate-shaped platen 520. A maintenance device 700 is provided on a left side of the platen 520 and six suction caps 710 are disposed on an upper face of the maintenance device 700 side by side in the lateral direction so as to correspond to the number of the printer heads which are mounted on the carriage 610. Each of the printer heads is connected with an ink cartridge (not shown) provided in the printer apparatus 500 through a supply tube (not shown).
At normal printing, the basic colors are frequently used (ejected) and relatively large quantities of their inks are consumed. However, the use frequencies of the special colors such as orange, blue and the like are often extremely low (hardly used) in comparison with the use frequencies of the basic colors. Therefore, like the printer apparatus 500 shown in FIG. 12, when the printer heads for the special colors which are hardly used at normal printing are previously mounted on the carriage 610 and connected with supply tubes and the suction caps 710 corresponding to the printer heads for the special colors are previously provided in the maintenance device 700, more cost than required is used and, in addition, there is much waste in an arrangement space in the lateral direction. As a result, its manufacturing cost is increased and the size of the printer apparatus 500 is made larger.